| Author | Message | ||
     Foximus |
Ok, so I just purchased a set of unused 04+ Screaming Eagle 1200 heads, complete with the beehive valves and all. So assuming they get here in a hurry, and I get my cylinders figured out, I will be well on my way in the build by Christmas. So that being said.... I'm wondering what kind of setup you guys would go for? I'm aiming for around 200psi. At sea level I believe this is about 12:1 . What pistons would be used to achieve this? If I stick with my OEM s1 pistons (flattop?) I believe this would make 10:1, But i'm not quite sure, the deck height might be completely different than that of the XB/04+ pistons. What gasket setup should I go for? I want the best sealing... I have my eye on the Cometic EST kit. From what I understand its the best of the best. I didn't really research these heads in relation to installation, as I bought them on a whim and didn't think I'd actually win the auction... so that being said, Am I going to need any different gaskets or modifying to be using these heads on the older cylinders? From my understanding the oil ports and mating surface all match up the same... And I believe the rocker boxes are interchangable as well.... Now I'm almost positive I remember reading somewhere I have to swtich to a different intake manifold... just don't remember which one? What about pushrods? Do I have to get shorter ones? Any other tips that you guys recommend for doing a ground up rebuild? | ||
| Phelan |
Get .040" under pushrods. If the heads are '04, the manifold should bolt up, but you will need a new front mount. What cams are you running? You will have a hard time getting 12:1 with any stock piston without having valve-to-piston clearance issues. For higher CR, forged is the way to go. Those heads are basically XB heads milled down for higher comp, so XB9 pistons most likely won't clear. Gaskets and cylinders should all match up, as well as the rockerboxes as you mentioned, though now would be a great time to switch the XB rockerboxes, and you could use an XB top end gasket kit to save some cheese. The new gaskets are pretty forgiving for installation from what I've been told. | ||
| Phelan |
BTW the stock S1 pistons with those heads should give you 10.5:1, because those heads are milled compared to stock XB/'04-up XL1200 heads. | ||
| Foximus |
Ah phelan great tips. Yes I know about the new mount, Though I am just considering making my own. Not sure if I will or not. Heads These are the heads I bought. From what I hear the xb9 pistons should make 14:1. And I was considering the recessed dome weisco's (though I think JE's might be a better make...?) Pistons But then there is also the Domed wiescos... but these may be similar to the XB9's? Looks like they would slam the slim bathtub combustion chamber pretty good Domed Wiescos I dont understand the benefit of the XB rocker boxes everyone is always talking about... as far as I understand its just a better venting case? Are the actual rockers lighter or something? What about new tappets/lifters? And I have Crane cam's, though I have no idea which or what grind. Guess I wont know until I open her up. I'm hoping I wont open my motor up to find my pistons in perfect condition, Or i might be tempted to keep using them with a hone and new rings.... but its blowing oil so bad I cant imagine they are good. | ||
| Brinnutz |
XB9 pistons make 11.7:1. No valve to piston problems. Ross, are you forgetting my motor build? You can use stock pushrods, depending on your cams I guess. | ||
| Foximus |
Perhaps... but if this head is a shaved version, then that could change. The cylinders I am getting have lightning head pistons in them... I believe thats with the 15* squish.... maybe its 10* i forget. or should I stick with flat tops? HD or buell specific? Looking at them I notice buell design pistons have more surface area and lands on the piston crown. | ||
| Phelan |
Fox, you're right, The stock lightning pistons do have about a 10* squish to them. Also Brin, as mentioned the Screamin' Eagle heads are XB heads that have been milled down, which is why they have higher compression, which is also why you need the shorter pushrods, because the standard XB heads are shorter than stock and only within the limits of the stock pushrods if you are using stock gaskets. So you will need different pistons. If the cam grind is over .500, you probably won't be able to use any of the stock pistons as the valve pockets won't be large enough. The lightning pistons you currently have also won't fit because of the squish band. Some Wiseco XB pistons or custom CPs would be my recommendation, or even some '04-up Screamin' Eagles. With those heads you will need a set of intake adapters. Call up Al and I'm sure he can source you some. I ordered some from NRHS 2 yrs ago and I believe they were like $15. | ||
| Phelan |
BTW the advantage of the XB rockerboxes is two-fold. One is less blow-by (almost none), while the other is that a two-piece box only has 2 gaskets, eliminating the middle gasket and less chance of leaks. Actually a third advantage is that there is more clearance under the XB rockerboxes for high lift cams. If using .536 lift or higher, you usually have to shave a little material off the underside of the stock rockerboxes. I had to clearance multiple spots when preparing the ones on my Sportster for the STD race heads I had. | ||
| Foximus |
A) Blow by considering of what? Surely not piston blow by... and probably not valve guide blow by... So i'm assuming you only mean vent blow by? Rocker boxes Is that all I would need? And use my existing top cover? B) Before you said my intake manifold will work... now you say it needs adapters? Are adapters just fatter or different intake seals? C) You are sure .040" pushrods are the correct length? Or should I go with adjustable so I can set my preload? D)I wont be able to use my normal s1 pistons now you think? These are the large beehive valves... Should I just call up NRHS and get a full run down of what they recommend? | ||
| Phelan |
Vent blow-by, aka spooge, is what I was talking about. Parts-wise you use your existing lower rockerbox and the XB top rockerbox and PCV valves, and replace the breather bolts in the side of the heads with solid bolts. The intake manifold miscommunication is because you originally listed the heads as '04 models, which would use the same intake as current, but your linked heads are '07 models, which will need the adapters because they were cut differently for the EFI intake. I believe the swish on the stock S1 pistons will make the smack the bottom of the combustion chamber, but I could be wrong. And yes, Dan@NRHS can clear all that up if you call him. | ||
| Phelan |
I was corrected on the pistons; they are flat tops, no squish band, so the stock pistons will work with the SE heads. | ||
| Foximus |
Yes.. I just read that in the XL forums thread too. But obviously not the Lightning head pistons.... Eitherway, after what ive read, I dont really like it... and that just pushes me to cancel the purchase since the seller is being fishy about not wanting to take pay pal. Anyone else have some 04+ heads? Ebay is empty of them.... (Message edited by Foximus on November 27, 2010) | ||
| Charlies_s1 |
Good move! | ||
| Foximus |
i figure so too... Now i just need to find me some normal heads. | ||
| Foximus |
Well... I guess nevermind about the normal heads... After almost 2 full weeks of being stubborn and him complaining and being a complete pain in the ass saying he wont take paypal... he decides he'll ship them out without payment... and then I'll ship him a money order after I recieve them. So it looks like I'll be running the screaming eagle heads anyway... Or at least reselling them...? |
